排序方式: 共有47条查询结果,搜索用时 15 毫秒
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N. Villa P. Riva D. Colombo E. Sala S. Mariani C. Zorloni F. Crosti L. Dalprà 《黑龙江环境通报》2001,21(10):801-805
The identification of small supernumerary marker chromosomes (SMCs) and the elucidation of their clinical significance remain two of the problems in classical human cytogenetics. We observed a small supernumerary ring in amniotic fluid cell cultures and identified its origin as r(2)(p10q11.2) and its extent by means of fluorescent in situ hybridisation (FISH). Uniparental disomy (UPD) was excluded by microsatellite analysis using polymorphic markers localised in the same region. On the basis of normal ultrasonographic checks, the patient decided to continue the pregnancy. A normal female was delivered at term and subsequent neonatal follow-ups confirmed the normal phenotype and development. In the present case, genetic counselling was not helpful because of the absence of reference cases. Detailed characterisation made it possible to correlate the normal baby phenotype with the trisomic 2p10-2q11.2 genomic region. Further molecular cytogenetic investigations of SMCs classified by DNA content and pregnancy outcome data should improve genetic counselling and risk evaluation. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Chuntian Cheng Jianjian Shen Xinyu Wu Kwok-wing Chau 《Journal of the American Water Resources Association》2012,48(3):464-479
Cheng, Chuntian, Jianjian Shen, Xinyu Wu, and Kwok-wing Chau, 2012. Short-Term Hydroscheduling with Discrepant Objectives Using Multi-step Progressive Optimality Algorithm. Journal of the American Water Resources Association (JAWRA) 48(3): 464-479. DOI: 10.1111/j.1752-1688.2011.00628.x Abstract: With increase in the number and total capacity of hydropower plants in power systems, optimality algorithms with a single objective are not suitable for optimizing the operation of complex hydropower systems to meet complex demands. Hydropower plants should prioritize discrepant objectives, such as peak regulation and maximizing generation during solving of optimal operation problems of hydropower systems. In this article, we present a multi-step progressive optimality algorithm (MSPOA) for the short-term hydroscheduling (STHS) problem to improve the quality of optimal solutions and enhance the convergence speed of progressive optimality algorithm (POA). In MSPOA, the original problem is first decomposed into a sequence of problems with the longer time steps. Next, the problem with the longest time step is solved, and the optimal solution is used as the initial solution for the problem with the second longest time step. This process proceeds until the original problem with the shortest time step is solved. The proposed discrepant-objective method and solution technique are tested for two types of hydroelectric systems. The results show that MSPOA can give better solutions and cost less time than POA due to enlarging feasible range of decision variables and reducing the number of computational stages. Discrepant objectives among hydropower plants can express the operation characteristics of complex hydropower systems more accurately than unique objective or multiple objectives. 相似文献
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不同寄主植物上烟蚜的染色体组型研究 总被引:6,自引:0,他引:6
对采自桃树、油菜和烟草上的烟蚜的核型研究表明:在红、黄绿两种体色的烟蚜中发现5种核型,即2n=12,正常;2n=12,A1与A3易位;2n=11;2n=13;3n=18,A1与A3易位。同时,在核型为2n=23的烟蚜中,体色为红色的个体全为A1与A3易位个体,体色为绿色的个体中既有A1与A3易位个体,又有正常个体。寄主植物不同的烟蚜的各条染色体相对长度在2n=12核型中差异不显著(α=0.05)。 相似文献
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The results of a karyological study on Siberian stone pines growing in the bog demonstrated differences from the populations of this species studied earlier with respect to sizes of chromosomes and location of secondary constrictions. The number of nucleolar organizer regions in the chromosomes of Siberian stone pine trees growing in the bog was larger than in other populations. A wide spectrum of chromosome aberrations was revealed, which had not been observed in this species before. These were genome and chromosome aberrations of various types, as well as structural aberrations accompanied by changes in the number of chromosomes. It is assumed that the aberrations in the karyotype of Siberian stone pine resulted from stressful conditions. 相似文献
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